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Abstract:

A system for preparing a refrigerant sample for analysis including a
pressure regulator assembly including a pressure regulator and provisions
for heating a refrigerant sample contained within an interior region of
the pressure regulator. The pressure regulator defines an inlet through
which the refrigerant sample is delivered and an outlet through which the
refrigerant sample is expelled. The system also includes a filter
assembly having an inlet that is fluidly connected to the outlet of the
pressure regulator to receive the vaporized refrigerant sample from the
pressure regulator, at least one filter for removing contaminants from
the refrigerant sample, and an outlet that is configured to be coupled to
a refrigerant analysis system for analyzing a composition of the
refrigerant sample.

Claims:

1. A system for preparing a refrigerant sample for analysis comprising: a
pressure regulator assembly including a pressure regulator and a means
for heating a refrigerant sample contained within an interior region of
the pressure regulator, said pressure regulator defining an inlet through
which the refrigerant sample is delivered and an outlet through which the
refrigerant sample is expelled; and a filter assembly having: an inlet
that is fluidly connected to the outlet of the pressure regulator to
receive the vaporized refrigerant sample from the pressure regulator, at
least one filter for removing contaminants from the refrigerant sample,
and an outlet that is configured to be coupled to a refrigerant analysis
system for analyzing a composition of the refrigerant sample.

2. The system of claim 1 further comprising a refrigerant analysis system
that is fluidly coupled to an outlet of the filter assembly for analyzing
a composition of the refrigerant sample.

3. The system of claim 1, wherein the pressure regulator assembly
includes a thermocouple for measuring a temperature value of the
refrigerant sample within the interior region of the pressure regulator.

4. The system of claim 3, further comprising a processor that
communicates with the thermocouple and the means for heating to regulate
the temperature of the refrigerant sample contained within the interior
region of the pressure regulator.

5. The system of claim 1, wherein the pressure regulator assembly
includes a metallic sleeve mounted around the pressure regulator, wherein
the metallic sleeve accommodates the means for heating.

6. The system of claim 1, wherein the means for heating is a heating
element.

7. The system of claim 1 wherein the filter assembly includes three
filters, and the filter assembly defines a fluid flow passageway that
intersects all three filters such that the refrigerant sample is
delivered through all three filters.

8. A method for preparing a refrigerant sample for analysis comprising
the steps of: introducing a refrigerant sample through an inlet of a
pressure regulator and into an interior region of the pressure regulator;
heating the refrigerant sample within the interior region of the pressure
regulator to vaporize the refrigerant sample; and distributing the
vaporized refrigerant sample through a filter to remove contaminants from
the refrigerant sample.

9. The method of claim 8 further comprising the step of distributing the
filtered and vaporized refrigerant sample into a refrigerant analysis
system for analysis.

10. The method of claim 8 further comprising the step of measuring a
temperature of either the pressure regulator or the refrigerant sample
within the interior region of the pressure regulator.

11. The method of claim 10 further comprising the step of regulating a
level of heat applied to the refrigerant sample as a function of the
temperature measurement.

12. A system for analyzing a refrigerant sample comprising: a pressure
regulator assembly including a pressure regulator and a means for heating
a refrigerant sample contained within an interior region of the pressure
regulator, said pressure regulator defining an inlet through which the
refrigerant sample is delivered and an outlet through which the
refrigerant sample is expelled; and a filter assembly having an inlet
that is fluidly connected to an outlet of the pressure regulator to
receive the vaporized refrigerant sample from the pressure regulator,
said filter assembly including at least one filter for removing
contaminants from the refrigerant sample; and a refrigerant analysis
system that is fluidly coupled to an outlet of the filter assembly for
analyzing the refrigerant sample.

13. The system of claim 12, wherein the pressure regulator assembly
includes a thermocouple for measuring a temperature value of the
refrigerant sample contained within the interior region of the pressure
regulator.

14. The system of claim 13, further comprising a processor that
communicates with the thermocouple and the means for heating to regulate
the temperature of the refrigerant sample within the interior region of
the pressure regulator.

15. The system of claim 12, wherein the pressure regulator assembly
includes a metallic sleeve mounted around the pressure regulator, wherein
the metallic sleeve accommodates the means for heating.

16. The system of claim 12, wherein the means for heating is a heating
element.

17. The system of claim 12 wherein the filter assembly includes three
filters, and the filter assembly defines a fluid flow passageway that
intersects all three filters such that the refrigerant sample is
delivered through all three filters.

Description:

FIELD OF THE INVENTION

[0001] The disclosed invention relates to a system and method for
preparing a refrigerant sample for analysis.

BACKGROUND OF THE INVENTION

[0002] A key element of the responsible use and stewardship of
refrigerants is the recovery, recycling and reclamation of used
refrigerants so that they can be reprocessed for further commercial use
or destroyed. It has become standard practice in the refrigeration system
service industry to recover and reclaim refrigerant for later reuse,
rather than merely to vent such refrigerant into the atmosphere, as had
been common practice in the past. Refrigerants can be recovered, recycled
and reclaimed from many systems, such as mobile air conditioners,
stationary air conditioners and refrigeration systems, for example. The
recovered refrigerant is then transported to a facility for reclamation.

[0003] The reclamation process typically encompasses an initial chemical
analysis of a sample of the recovered refrigerant in an effort to
identify the composition of the recovered refrigerant that is to be
reclaimed. The following steps are commonly performed to prepare the
refrigerant sample for analysis: (1) drawing a sample of liquid
refrigerant, (2) injecting the sample into a sample bomb, (3) vaporizing
the sample in the bomb, (4) filtering the vaporized sample to remove
contaminants, such as lubricants, water and metallic particles, and (5)
manually introducing the filtered sample into an analytical instrument
for analysis, such as mass spectroscopy and gas chromatography.
Contaminants, such as oil or other lubricants are filtered from the
vaporized sample in step 4 because those contaminants could impair the
chromatography process.

[0004] The foregoing preparation steps are time consuming, typically
consuming 90 minutes or more, and, for that reason, only a small fraction
of recovered refrigerant may be analyzed. In order to comply with
ever-increasing regulatory demands it has become necessary to conduct a
more comprehensive analysis of the recovered refrigerant that is to be
reclaimed. Such regulatory demands are defined in Air-conditioning,
Heating and Refrigeration Institute (AHRI) Standard No. 700-2006. Thus,
there is a need in the industry for a refrigerant sample preparation
system that can be employed to more rapidly prepare recovered refrigerant
for analysis.

SUMMARY OF THE INVENTION

[0005] According to an aspect of the invention, a system for preparing a
refrigerant sample for analysis is provided. The system comprises a
pressure regulator assembly including a pressure regulator and means for
heating a refrigerant sample contained within an interior region of the
pressure regulator. The pressure regulator defines an inlet through which
the refrigerant sample is delivered and an outlet through which the
refrigerant sample is expelled. The system further comprises a filter
assembly having an inlet that is fluidly connected to the outlet of the
pressure regulator to receive the vaporized refrigerant sample from the
pressure regulator, at least one filter for removing contaminants from
the refrigerant sample, and an outlet that is configured to be coupled to
a refrigerant analysis system for analyzing a composition of the
refrigerant sample.

[0006] According to another aspect of the invention, a method for
preparing a refrigerant sample for analysis is provided. The method
includes the step of introducing a refrigerant sample through an inlet of
a pressure regulator and into an interior region of the pressure
regulator. The refrigerant sample within the interior region of the
pressure regulator is heated to vaporize the refrigerant sample. The
vaporized refrigerant sample is distributed through a filter to remove
contaminants in the refrigerant sample.

BRIEF DESCRIPTION OF THE DRAWINGS

[0007] The invention is best understood from the following detailed
description when read in connection with the accompanying drawing.
Included in the drawing are the following figures:

[0008]FIG. 1 is a schematic view of refrigerant sample preparation system
according to one exemplary embodiment of the invention;

[0009] FIG. 2 is a top plan view of a heated pressure regulator of the
system of FIG. 1;

[0010]FIG. 3 is a cross-sectional view of the heated pressure regulator
of FIG. 2 taken along the lines 3-3;

[0011] FIG. 4 is a cross-sectional view of the heated pressure regulator
of FIG. 2 taken along the lines 4-4; and

[0012]FIG. 5 is a cross-sectional view of the filter assembly of FIG. 1.

DETAILED DESCRIPTION OF THE INVENTION

[0013] The invention is best understood from the following detailed
description when read in connection with the accompanying drawing, which
shows exemplary embodiments of the invention selected for illustrative
purposes. The invention will be illustrated with reference to the
figures. Such figures are intended to be illustrative rather than
limiting and are included herewith to facilitate the explanation of the
present invention. In the various embodiments like item numbers represent
substantially similar features.

[0014]FIG. 1 is a schematic view of refrigerant sample preparation system
according to one exemplary embodiment of the invention. The refrigerant
sample preparation system, which may be referred to hereinafter as a
system, is denoted by the numeral `10.` According to one exemplary
embodiment of the invention, the system 10 generally includes a sample
container 11 filled with a refrigerant sample, a heated pressure
regulator assembly 12 that is fluidly coupled to sample container 11 for
heating a refrigerant sample, a filter assembly 14 having an inlet port
21 that is fluidly coupled to pressure regulator assembly 12 via conduit
15 for filtering the heated refrigerant sample, and a conduit system 16
that is fluidly coupled to filter assembly 14 to provide a passageway for
venting and vacuuming of system 10. A conduit 17 is fluidly coupled
between an outlet port 18 of filter assembly 14 and an analytical
instrument 20. The analytical instrument 20 may be a mass spectrometer, a
gas chromatograph, or a flame ionization detector, for example. According
to one aspect of the invention, analytical instrument 20 is a mass
spectrometer and a gas chromatograph.

[0015] The conduit system 16 comprises a series of interconnected
fluid-carrying pipes 13 and discrete valves 19a-19e mounted to
fluid-carrying pipes 13. The conduit system 16 is fluidly coupled to a
vacuum source 22, which is configured to evacuate filter assembly 14 and
pressure regulator assembly 12. The conduit system 16 is also fluidly
coupled to a venting container 24 for collecting refrigerant sample that
is utilized for flushing filter assembly 14 and regulator assembly 12.
The venting container 24 may be a refrigerant reclamation system, for
example. A series of discrete valves 19a-19e, which are maintained in
either an open position or a closed position, are provided on conduit
system 16 to facilitate vacuuming and venting operations of filter
assembly 14 and pressure regulator assembly 12. The discrete valves
19a-19e normally remain in a closed position to prohibit the passage of
fluid thereacross. During a vacuum stage, however, discrete valves 19a,
19b, 19c and 19e are open and valve 19d is closed, and during a venting
stage, discrete valves 19a-19d are open and valve 19e is closed. The
valves 19a-19e may be automated by processor 23 or operated manually.

[0016] Although not shown, another discrete valve may be provided on
sample container 11 or on the conduit between sample container 11 and
regulator assembly 12 to prevent the passage of refrigerant into
regulator assembly 12. Another discrete valve may also be provided on
analytical instrument 20 or on conduit 17 to prevent the delivery of
refrigerant into instrument 20.

[0017] Referring now to FIGS. 2-4, FIG. 2 depicts a top plan view of a
heated pressure is regulator assembly 12 of FIG. 1, and FIGS. 3 and 4
depict cross-sectional views of heated pressure regulator assembly 12 of
FIG. 2 taken along the lines 3-3 and 4-4, respectively. The heated
pressure regulator assembly 12 includes a pressure regulator 30 that is
at least partially encased within a heated sleeve 32. The pressure
regulator 30 includes an inlet port 40 through which refrigerant sample
is distributed into the interior of pressure regulator 30, an outlet port
42 through which the refrigerant sample is expelled from the interior of
pressure regulator 30, a valve (not shown) for selectively permitting the
passage of the refrigerant sample between inlet port 40 and outlet port
42, and a knob 43 for adjusting the pressure setting of pressure
regulator 30. Operation of a pressure regulator is understood by those
skilled in the art. A suitable pressure regulator may be offered by the
Tescom Corporation of McKinney, Tex., USA.

[0018] The heated sleeve 32 is generally cylindrical and is composed of a
conductive material, such as aluminum, for example. The sleeve 32 is
heated by two heating elements 35. As best shown in FIG. 3, thermal
contact is established between the revolved interior surface of heated
sleeve 32 and the revolved exterior surface of regulator 30 at interface
36 such that thermal energy is transferred from sleeve 32 to regulator
30. The pressure regulator 30 is also composed of a conductive material
such that thermal energy is transferred from the exterior surface of
pressure regulator 30 to refrigerant that is contained within pressure
regulator 30. The sleeve 32 at least partially encapsulates regulator 30
to evenly distribute heat across the entire revolved surface of pressure
regulator 30. According to this exemplary embodiment, sleeve 32 extends
around the entire circumference of pressure regulator 30, with the
exception of two apertures 33 that are disposed at the lower end of
sleeve 32 to accommodate inlet port 40 and outlet port 42 of regulator
30.

[0019] Two bores 34 (two shown) are formed in heated sleeve 32, wherein
each bore 34 accommodates a single heating element 35. The heating
elements 35 are positioned on opposing sides of heated sleeve 32 (see
FIG. 2), and extend a substantial portion of the length dimension of
heated sleeve 32 (see FIG. 4) to uniformly heat the surfaces of pressure
regulator 30, as well as the refrigerant sample that is contained within
regulator 30, to a pre-determined temperature. The heated sleeve 32 may
accommodate any number of heating elements and is not limited to the
embodiment shown and described herein. A thermocouple 38 is mounted to
the top exterior surface of heated sleeve 32. The thermocouple 38 is
configured to measure a temperature of sleeve 32 and transmit that
temperature measurement to a computer processor 23 of system 10. The
processor 23 controls the amount of heat emitted by heating element 35 as
a function of the temperature is measurement recorded by thermocouple 38.

[0020]FIG. 5 depicts a cross-sectional view of filter assembly 14 of FIG.
1. The filter assembly 14 generally includes a housing 50 defining an
interior fluid passageway within which three coalescing filter cartridge
assemblies 53a-53c are positioned in series, an inlet port 21 coupled to
housing 50 through which the heated refrigerant sample is delivered into
the fluid passageway, and an outlet port 18 coupled to housing 50 through
which the filtered and heated refrigerant sample is expelled. In
operation, heated refrigerant sample is delivered through inlet port 21,
through filter cartridge assemblies 53a-53c in sequential order and
expelled through outlet port 18. In FIG. 5, the flow path of the
refrigerant sample through the filter assembly 14 is indicated by arrows.

[0021] The housing 50 is a machined block of aluminum, for example. Three
openings 55a-55c are defined in housing 50. One bore 67 is defined in a
wall of housing 50 between openings 55a and 55b, and another bore 69 is
defined in a wall of housing 50 between openings 55b and 55c. One
coalescing filter cartridge assembly 53a-53c is positioned within each
opening 55a-55c, respectively. Each coalescing filter cartridge assembly
53a-53c includes a coalescing filter 56a-56c mounted to a cartridge
57a-57c, respectively. An annular shoulder 59 is provided on the bottom
end of each cartridge 57a-57c for mounting a coalescing filter 56a-56c,
respectively. The filters 56a-56c may be adhered or merely positioned on
annular shoulder 59 of cartridges 57a-57c, as shown. The coalescing
filters 56a-56c have a substantially annular shape. The term `coalescing`
denotes the separation of liquid aerosols and droplets from a gas stream.
The coalescing filters 56a-56c have a borosilicate glass filter element
(fiber), manufactured (for example) by the Parker Hannifin Corporation.

[0023] Each cartridge 57a-57c includes a substantially cylindrical body
defining an interior fluid passageway 58 extending from one inlet 63 and
a plurality of outlets 65 (four shown). In each coalescing filter
cartridge assembly 53a-53c, an annular space 66 is defined between the
exterior surface of cartridge 57a-57c and the interior surface of filter
56a-56c. In operation, heated refrigerant is directed from outlets 65 of
cartridges 57a-57c into annular space 66. Another annular space 68 is
defined between the exterior surface of filter 56a and the surface of
opening 55a of each coalescing filter cartridge assembly 53a-53c. In
operation, heated refrigerant passes through filter 56a-56c and collects
in annular space 68.

[0024] An outlet fitting 70a-70c is fixed to housing 50 and is fluidly
connected to the bottom end of opening 55a-55c, respectively. Each outlet
fitting 70a-70c is fluidly coupled to a discrete valve 19a-19c,
respectively (see FIG. 1). In an open position of one or more discrete
valves 19a-19c, fluid is expelled from filter assembly 14 and is
distributed through conduit system 16. Conversely, in a closed position
of all three discrete valves 19a-19c, fluid is prevented from entering
conduit system 16.

[0025] Referring now to the operation of refrigerant sample preparation
system 10 with reference to FIGS. 1 and 5, at start-up of system 10,
heating elements 35 are activated and discrete valves 19a-19e are closed.
Once regulator assembly 12 reaches a pre-determined temperature, as
measured by thermocouple 38, the liquid-phase oil-laden refrigerant is
directed from container 11 into regulator assembly 12. Once the
liquid-phase oil-laden refrigerant is heated within regulator assembly 12
to a pre-determined temperature, as measured by thermocouple 38, the
refrigerant undergoes a phase change from a liquid state to a vapor
state. It should be understood that heating the refrigerant increases its
flow rate through system 10, which increases the speed of the refrigerant
sample preparation process. Once the refrigerant reaches a vapor state,
the oil-laden vapor-phase refrigerant is distributed through filter
assembly 14. More particularly, the heated vapor-phase refrigerant is
distributed through inlet port 21 of filter assembly 14 and into fluid
passageway 64 of cover 60a. The heated refrigerant enters inlet 63 of
fluid passageway 58 of cartridge 57a and exits through outlets 65 of
fluid passageway 58 of cartridge 57a into annular space 66 of coalescing
filter cartridge assembly 53a. The heated refrigerant flows across filter
56a and enters annular space 68 of coalescing filter cartridge assembly
53a. This represents the first pass of the refrigerant through a filter.
Because discrete valve 19a is maintained in a closed position, the
refrigerant is urged upwards through bore 67 of housing 50.

[0026] The once-filtered, heated refrigerant then enters fluid passageway
64 of cover 60b, travels through inlet 63 of fluid passageway 58 of
cartridge 57b and exits through outlets 65 of fluid passageway 58 of
cartridge 57b into annular space 66 of coalescing filter cartridge
assembly 53b. The heated refrigerant flows across filter 56b and enters
annular space 68 of coalescing filter cartridge assembly 53b. This
represents the second pass of the refrigerant through a filter. Because
discrete valve 19b is maintained in a closed position, the refrigerant is
urged upwards through bore 69 of housing 50.

[0027] The twice-filtered, heated refrigerant then enters fluid passageway
64 of cover 60c, travels through inlet 63 of fluid passageway 58 of
cartridge 57c and exits through outlets 65 of fluid passageway 58 of
cartridge 57c into annular space 66 of coalescing filter cartridge
assembly 53c. The heated refrigerant flows across filter 56c and enters
annular space 68 of coalescing filter cartridge assembly 53c. This
represents the third pass of the refrigerant through a filter. By the
third pass, contaminants, such as oil or other lubricants, are
substantially removed from the vapor-phase refrigerant. Because discrete
valve 19c is maintained in a closed position, the refrigerant is urged
upwards through outlet port 18 of filter assembly 14 and into conduit 17.
The filtered refrigerant is then distributed into analytical instrument
20 (see FIG. 1) for analysis.

[0028] Once analysis of the refrigerant sample is complete, the system is
readied for another dose of a refrigerant sample (referred to hereinafter
as the second refrigerant sample or the second dose). Prior to injecting
system 10 with the second dose of refrigerant, system 10 is vacuumed,
flushed and vented to remove any remainder of the previous refrigerant
sample. More particularly, to prepare the system for the second dose, the
contents of filter assembly 14 and regulator assembly 12 are first
evacuated to remove the bulk of the previous refrigerant sample. In a
vacuuming procedure, discrete valves 19a-19c and 19e are opened, discrete
valve 19d is closed, a discrete valve (not shown) positioned between
container 11 and regulator assembly 12 is closed, and vacuum source 22 is
activated. The vacuum source 22 draws a vacuum through conduit assembly
16. The contents within filter assembly 14 and regulator assembly 12 are
evacuated through conduit assembly 16. The discrete valves 19a-19c may be
opened either simultaneously or sequentially while vacuum source 22 is
activated.

[0029] Thereafter, system 10 and analytical instrument 20 are flushed with
the second dose to remove any residual of the previous refrigerant
sample. To flush system 10 and analytical instrument 20, discrete valves
19a-19e are closed, and a limited quantity of the second dose is
distributed through system 10 and analytical instrument 20. Thereafter,
system 10 and analytical instrument 20 are vented by opening discrete
valves 19a-19d. Venting system 10 and analytical instrument 20 exposes
system 10 and analytical instrument 20 to atmospheric pressure to obtain
a consistent volume of the second dose in analytical instrument 20. The
second refrigerant dose exhausts into venting container 24. After the
final venting step, the system 10 and analytical instrument 20 are now
sufficiently free of the previous refrigerant sample and ready to analyze
the remainder of the second dose of refrigerant. The remainder of the
second dose is distributed through system 10 into analytical instrument
20. This process may be repeated continuously.

[0030] While preferred embodiments of the invention have been described
herein, it will be understood that such embodiments are provided by way
of example only. Numerous variations, changes and substitutions will
occur to those skilled in the art without departing from the spirit of
the invention. For example, the system disclosed herein is not limited to
distributing refrigerant. The system may also be configured to distribute
liquids, gases, flammable or non-flammable fluids, water, industrial
mixtures, hydrocarbon mixtures, reactor gas mixtures or any other fluid.
It is intended that the appended claims cover all such variations as fall
within the spirit and scope of the invention.